Process of casting copper bars, ingots, and other articles.



UNITED sTA'rEs'PATENT OFFICE.

LAWRENCE nnnroKs," tar-E IZAB TH, Ann AUGUST nanxsorcnnoivm, New-mess l ,ASSIGNTORS TO U'nIr tote A we Ne. Drawingi To all whom may 'co ncc' rziju Y (Bait known that'we, LAWRENCE, Anoroxs, acitlzen ofthe-qUnitedfiStates, residing at Elizabeth, in; the bounty of: Union and State ofNew dei sey g-ti'nd AUGUST MARKS, a citi-i ""lenof t'he United States, residing at Chrome,

iii-the counfiy ofMiddlesexand State of New J ei sey li ave invented certain new and usefiiil li nprovements in Processes of Casting Copper Bars, Ingots, and other Articles, of

which the'following is a full, clear, and exact description.

"In the production of ingots, etc.',' from the cathodes producedin electrolytic refining processes, the cathodes "are melted down, preferably in a suitable reverberatory furnace," and from the furnace the" metal" is poured out into the proper molds. Thecathodes are substantially pure, but" carry nevertheless small amounts of occluded or entrapped electrolyte, and additional impurities also find their way into the mblten mass, as fromthe gases of combustron,jet c. These forelgn substances are removed'before the metal 1s cast Into the de- "sired" ingots or bars, and the removal is usually efl'ected by an oxidizing or scorifying process. For this purpose air is blown through .the molten metal, with the result that cnprous oxid is formed'which acts as a' s'corifying agent, the oxidized impuritiesfioating on the bath. Theresulting slag collects on the surface of the metal and is skimmed oil in the, usual way, the bath retaining considerable CUPIOHS oxid in solution. The degree of oxidation must now. be ascertained, and this can eifected by observing the set of the copper. When the metal cools in the open mold itshrinks more or less, giving the. top a wrinkled appearance, commonlyknown as the set. If the set isltoo low, that is, if the wrinkles or foldsare too deep, the presence of too much oxid is indicated, and more or less ofthe sam'e must be reduced. This is done usually poling is carried too far, too much of the oxids is reduced and the "set becomes high in'w'hich case ispews ,-oi" Worms]? may be thrust out 'ofthe solidifying metal,

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Specification or LettersPatent. l PatentedtlaniB; 1911}? I, Application filedihme 23, 1910.: Serial Ho; 5618.355." l 1 5 i which, in the subsequent rolling of the bar or ingot, produce slivers or similar defects in the rolled product. The set isthus a criterion of the condition of the metal, showing whether or not it possesses the necessary degree of. dissolved oxid to make perfect castings-. 1 t

Heretofore the practice has always been to operate the furnace by charges, or. on the fill and empty principle, the peculiar sensitiveness of copper and the difficulty of controlling the set having led to the belief, universal among-foundrymen in this art, that it was impossible to make the process continuous, or even lengthen the period of operation without proportionately diminishing We have discovered however, that the o eration can be extended with the result 0 greatly increasing the per diem output, and can even be; continued indefinitely within limits set by the durability of the furnace, labor conditions, etc.

The essential feature of our processis the addition of solid metal to the molten metal in the furnace from timeto time during the casting, the'sum total of the additions being sufficient in amount to keep the furnace in operation for the desired length of time. For example, if the process'i's to be continuous the additions are made suflicient in amount to compensate, in the long-run, for

the withdrawals. t

.As a specific example of our processwe will now describe the procedure which we are employing with complete success, increasingv the output enormously without impairing the quality of the product. In starting, the furnace employed is char ed with cathode copper to the amount 0 340,000 pounds-or thereabout. When this charge is melted the molten metal-is scorified and in theusual way poled to bring the metal to the desired condition of purity as evidenced "by the set. Some 10,000 poundsof the metal 1 may be 330,000 pounds, more or less, 1n the furnace.

consumed in this step, leaving These operations take about eighteen hours more oril'ess. I The casting is now begun, atthe rate of about 70,000 pounds anhour, and after'half an hour unmelted cathode copper,

' to the amount of say 40,000 ounds, is -added tof 'thezz molten copper in t e furnace -,In making this, and subsequent additions of solid 1' metal, the-cathodes are stacked one on top of another and the stack or stacks are introduced through a suitable opening in the furnace wall, such opening being closed at othertimes. On being deposited in-the furnace the stack of cathodes sinks-into the molten metal and most of the stack, if not all, is submerged, the submerged portion being thus protected from oxidation or other efiects of the gases of combustion flowing through the furnace. The pouring or casting now proceeds'at the rate mentioned, and in about three quarters of an hour another addition of 40,000 poundsof cathode copper is made, and an hour and a quarter later a third addition of the same amount. 120,000 pounds have now been added to the 330,000 pounds remaining after the scorification, and, at the rate of 70,000 pounds per hour, 175,000 pounds have been withdrawn, leaving some 27 5,000 pounds of metal in the furnace. At this point the additions may cease and the casting continue, in which case the furnace is emptied within the next four hours, the total operation occupying twentyfour and a half hours withan output of 450,000pounds, as against twenty-two and a half or three-quarters hours and an output of 330,000 pounds by the old method, or, if desired, the additions may be continued in the same amounts, but preferably in smaller amounts so as to bring the run to an end gradually. During the operation care is exercised to keep up the fire to maintain the metal in the furnace at a suitable casting temperature, and if the set shows signs of becoming too low the metal is poled to the extent needed to keep the set within the limits of permissibledeparture from the standard. The set will hardly become too high except as the result of unskilful or too prolonged poling. v

As stated, the process may be continued as long as desired by keeping" up the additions of solid copper. In general we prefer to add enough solid metal, at suitable intervals, to increase the period of operation and the output in about the proportion described above. The method may also be employed to advantage in the casting o anodes from pig copper, anode scrap, etc.

'What is claimed is:

' 1. The herein described process of making ingots, bars, and other copper articles of a substantially constant degree of purity of the metal, comprisingmeltlng amass of copper having the requisite degree of purity,

drawing oif the molten copper in'relatively small amounts into suitablemolds, and from time to time adding solid copper to the molten mass,"'while maintaining the heat of the mass at a proper casting temperature.

2. The herein described process of making ingots, bars, and other copper articles of a substantially constant degree of purity of taining the heat of the mass at a the metal, comprising melting amass of electrolytically refined or cathode copper, drawing oil the molten copper in relatively small amount into suitable molds, and adding solid cathode copper to the molten mass from time to time, While maintaining the heat of the mass at a perature.

3. The herein described continuous rocess of making fine copper bars, ingots, an other articles, comprising melting a mass of electrolytically refined or cathode copper, drawingofi the molten copper into suitable molds, adding solid cathode copper to the molten mass to replenish the same, while maintaining the heat of the mass at a proper casting temperature, and from time to time treating the molten mass with suitable reagents to maintain the proper oxid content therein.

l. The herein described process of making ingots, bars, and other copper articles of a substantially constant degree of purity of the metal, comprising melting a mass of copproper casting tem-- per having the requisite degree of purity,

drawing off the molten copper in relatively .small amounts into suitable molds, and from time to time adding solid copper to the molingots, bars, and other copper'articles of a substantially constant degree of purity 'of the metal, comprising melting a mass of electrolytically refined or cathode copper,

drawing themolten copper in relatively small'amounts into suitable molds, and from time to time adding solid cathode copper to the molten mass by submerging the cathodes more or less in the molten metal, while mainproper casting temperature.

6. T heherein described process of making ingots, bars and other copper articles of a substantially constant degree of purity of the metal, comprising melting a mass of electrolytically refined. or cathode copper treating the molten mass to remove impurities therefrom, drawing off'the molten cop per in relatively small amounts into suitable molds, and addin solid cathode copper to the molten mass irom time to time, while maintaining the heat of the mass at a proper casting temperature.

In testimony whereof we afiixour signatures in the presence of two subscribing witnesses.

LAWRENCE ADDICKS,

Witnesses:

EDWARD J. B LFIN, A. XV. DEACOX.

AUGUST MARKS. 

